JPS6298321A - Optical path switching device for lighting equipment - Google Patents

Abstract

PURPOSE:To light plural bodies by one light source through simple constitution by providing plural optical fibers to an aperture part through which illumination light from the light source is passed, and moving light incidence end of the optical fibers selectively and switching optical paths. CONSTITUTION:The light emitted by the light source 1 is converged on the slit aperture 4A. An optical path switching member 5 is provided right under the slit aperture 4A and slid by a driving device 6 as shown by an arrow (d), and both ends of the member 5 are fitted to optical fibers 7 and 5. When the incidence end 7A of the optical fiber 7 is right under the aperture 4A, light passed through the fiber 7 and exists from its projection end 7B. Then, the light is reflected by a half-mirror 11 to light a body W1 to be detected. Reflected light from the object W1 is guided to a photoelectric converting element 14, which performs image processing. Similarly, light passed through the optical fiber 8 illuminates an object W2. For the purpose, the incidence ends of the optical fibers are moved to switch optical paths of illuminations, so plural bodies are easily lighted by one light source.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an optical path switching device for an illumination device capable of illuminating different objects or positions through a plurality of illumination optical systems provided in one device.

[Background of the invention]

An illumination device is configured such that a plurality of optical systems are provided in one device, each different object or position is illuminated through the plurality of optical systems, and the illuminated object or position can be observed or detected. For example, special public relations
This method has been known for a long time, as disclosed in Japanese Patent No. 24 (Improvement of Comparative Microscope). However, like the illumination device disclosed in this publication, one
When one illumination light source is provided for each illumination optical system, multiple light source devices are required, which not only makes the device expensive, but also requires exaggerated heat countermeasures for the entire device. There is.

Therefore, as a solution to the above drawbacks, multiple illumination optical systems that directly receive light emitted from a single light source in different directions are provided, and different objects or positions can be illuminated through each illumination optical system. A lighting device configured as shown in FIG. However, in this known illumination device, in order to alternately illuminate different objects or positions, it is not only necessary to provide each of the plurality of illumination optical systems with shutters that open and close in conjunction with each other, but also to The disadvantage is that each illumination optical system that guides the light has a complicated configuration.

[Purpose of the invention]

The present invention solves the drawbacks of the conventional lighting devices described above, and provides an optical path for a lighting device that can alternately switch and illuminate each object or position through a plurality of illumination optical systems using a single light source and with an extremely simple configuration. The purpose is to provide a switching device.

[Summary of the invention]

In order to achieve the above object, the present invention includes an aperture member having an aperture through which illumination light from a light source passes, and a plurality of flexible optical fibers each guiding the light passing through the aperture to a plurality of test objects. , and an optical path switching means that holds the light input ends of the plurality of optical fibers and is selectively movable so as to align the light input ends with the apertures, respectively, and moves the light input ends of the optical fibers. The technical point is to configure the illumination optical path so that it can be switched by.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, and shows the case of an apparatus having two illumination optical systems, and FIG. FIG. 1 is a block diagram of an alignment device incorporating an embodiment device.

In FIG. 1, light emitted from a light source 1 passes through an infrared cut filter 2 and is focused by a condenser lens 3 onto a slit opening 4A provided in an aperture member 4. An optical path switching member 5 is provided directly below this slit opening 4A, and this optical path switching member 5 is configured to slide in the direction of arrow d by a drive device 6. Further, one input end 7A and 8A of two optical fibers 7 and 8 are attached to both ends of this illumination optical path switching member 5,
The input end 7A of one optical fiber 7 is the slit opening 4A.
When located directly below the light source 1, the light from the light source 1 passes through one of the optical fibers 7 and passes through the one illumination lens 10.
The injection end 7B is fixed in the vicinity of the injection end 7B. Also,
The input end 8A of the other optical fiber 8 is the slit opening 4A.
When the illumination light passes through the slit opening 4A, it passes through the other optical fiber 8 and is emitted from the exit end 8B fixed close to the other illumination lens 20. Further, when the intermediate portion 5A of the optical path switching moving member 5 is located directly below the slit opening 4A, the light from the light source 1 is blocked by this intermediate portion and does not enter the optical fiber half 8.

The illumination light emitted from the exit end 7B of one of the optical fibers 7 is once condensed by the illumination lens 10, reflected by the half mirror 11, passes through the objective lens 12, and becomes a nearly parallel light beam to be examined. Illuminate the object (wafer) W+. Similarly, the illumination light emitted from the exit end 8B of the other optical fiber 8 is once condensed by the illumination lens 20, reflected by the half mirror 21, and further passed through the objective lens 22 to be approximately parallel. It becomes a light beam and is placed on the surface of the object to be inspected (wafer). The light reflected from the test objects W, , W2 passes through the pupils of the objective lenses 12.22, and then through the half mirrors 11, 21, and then passes through the imaging lenses 13.23 to the test objects W1, W2. The light is focused on the light-receiving surface of the photoelectric conversion element 14.24 placed at a position image conjugate to the object W, ,
The image of W2 is projected onto the photoelectric conversion element 14.24. The detection signals from the photoelectric conversion elements 14 and 24 are input to a processing device to be described in detail later and undergo image processing, or are observed as an image of the object on a television or the like (not shown).

FIG. 2 shows an embodiment incorporated into a wafer alignment device used in a wafer blobbing process. A loading device 50 includes a wafer supply arm 52 that takes out a wafer from a cassette 51, and a wafer supply arm 52 that takes out a wafer from a cassette 51, and a wafer supply arm 52 that takes out a wafer from a cassette 51, and a wafer supply arm 52 that takes out a wafer from a cassette 51. a pre-alignment stage 53 on which wafers W, , W2 are placed and pre-aligned based on the outline of the wafer and the orientation flat;
including a stage 54A and a second stage 54B,
The supply arm 52 is configured to load (i! place) a wafer on which prealignment has been completed onto the vacant stage of the stages 54A and 54B. Wafers W, W placed on stages 54A and 54B
The pattern on 2 is illuminated by light from the light source 1 that is selectively sent through the optical fiber 7.8, and the image information of the pattern is transmitted to the first solid-state image sensor (first photoelectric conversion element) 14 and the second solid-state image sensor 14. Image sensor (first photoelectric conversion element) 2
Read by 4.

It will be done. Furthermore, a first stage control device 55A that controls the first stage 54A and a second stage control device 55A that controls the second stage 54B are provided.
The stage control device 55B is a CPU (central processing unit) 6
3, respectively. The interface 61, memory 62, and CPU 63 constitute an alignment information processing device 60. In addition, the stage control devices 55A and 55B include CPUs 56A and 56B for stage control, and an interface 57A157, respectively.
B and stage drive devices 58A and 58B.

Next, the operation of the alignment device shown in FIG.
This will be explained based on the flowchart shown in FIG.

The optical path switching moving member 5 is placed in such a state that the intermediate portion 5A is located directly below the slit opening 4A of the opening member 4, so when the cassette 50 is installed in the loading device 50 and the device is started, the light source 1 is turned on. However, the light is blocked by the intermediate portion 5A. Therefore, when the apparatus is started, the CPU 63 determines whether or not uninspected wafers are stored in the cassette 51 (step 101).
), when a positive result is obtained, the CPU 63 determines whether the pre-alignment stage 53 is vacant (step 102).

If a positive result is obtained, the CPU 63 controls the wafer supply arm 52 to take out the uninspected wafer into the cassette 51 and load it onto the pre-alignment stage 53 (step 103).

When this loading is completed, a pre-alignment device (not shown) performs pre-alignment of the wafer placed on the stage 53 (step 104).

Next, the CPU 63 determines whether the first stage 54A is vacant (step 105).

If a negative result is obtained, the CPU 63 proceeds to the second stage 54.
It is determined whether or not B is vacant (step 106).

The processing when a positive result is obtained in both steps 105 and 106 is exactly the same, so after the code that appears in the process that follows step 105, the code that appears in the process that follows step 106 is placed in parentheses. Write it down to avoid repeating the explanation.

If a positive result is obtained in step 105 (106)
Then, the wafer supply arm 52 transfers the pre-aligned wafer from the stage 53 to the stage 54A (54B).
) [step 107 (108)).

When this loading is completed, the CPU 63 sends a signal to the optical path switching drive device 6 to slide the optical path switching moving member 5 to move the optical path switching member 5 to the input end of the optical fiber 7 (8). A
(8A) moves its entrance end 7A (8A) so that it coincides with the slit opening 4A of the aperture member 4, and passes it through the optical fiber 7 (8) and the half mirror 11 (21) onto the stage 54A (54B). The wafer W, (wz) is illuminated [step 109 (110)). Wafer W+
When the stage control value L; 24) Scanning is performed in a direction perpendicular to the element arrangement direction. On the other hand, CPU6
3, the pattern of the wafer W, (WZ) on the stage 54A (54B) is transferred to the solid-state image sensor 1 in synchronization with this scanning.
4 (24) and store the image information of the pattern in the memory 62 via the interface 61.
Step 111 (112)).

When the reading of the pattern of wafer "#+ (Wz) is completed, the CPU 63 performs arithmetic processing for fine alignment of wafers W and (WZ) based on the image information in the memory 62, that is, the pattern of wafer W+ (Wz). [Step 113 (114)], and the calculation result is sent to the CPU 56A of the stage control device 55A (55B).
(56B) [Step 115 (
116-)].

When this transfer is completed, the CPU 56A (56B) controls the stage drive device 58A (58B) via the interface 57A (57B) separately and independently from the CPU 63, and the stage 54A (54B) drives the wafer W+(W).
Perform fine alignment of Z) [Step 117 (
118)). When fine alignment is completed, CP
tJ63 sends a signal to the optical path switching drive device 6,
The optical path switching moving member 5 is moved back to a position where its intermediate portion 5A coincides with the slit opening 4A, and the wafer W1 (W
The illumination light from the light source 1 illuminating the Z) is blocked [step 119 (120)). At that time, the input ends 7A and 8A of the optical fiber 7.8 are removed from the slit opening 4A, so
Both wafers W,,W.

are not illuminated together.

When the blocking of the illumination light is completed in step 119 (120), control is transferred to an inspection device such as a blower set (not shown) prepared for the stage 54A (54B), and the inspection device detects the pattern on the wafer W+ (wz). [Step 121 (1)
22)). This inspection device is prepared separately for wafers W and WZ, so both wafers W1 and WZ are inspected separately.
Z inspection can be performed simultaneously. During the floating process by this inspection device, the stage 54A (54B) is operated in conjunction with the inspection operation of the CPU 56A (56B) inspection device.
control and make it perform the operations necessary for inspection.

The program for driving the stage is written in advance by the CPU 5.
6A and 56B.

On the other hand, when the CPU 63 transmits the illumination light cutoff signal in step 119 (120), it determines whether the inspection of the wafer WI placed on the first stage 54A has been completed (step 123). In addition, each judgment step 10 above
Even if a negative result is obtained in the judgment of 1.102.106, the step is to be taken to step 123. When a negative result is obtained in step 123, the CPU 63 determines whether the inspection of the wafer W2 on the second stage 54B has been completed (step 124).

If a positive result is obtained in step 123 (or step 124), the CPU 63 controls the wafer supply arm 52 to feed the wafer Wl (WZ) from the stage 54A (54B).
) is then transferred to the cassette 51 or another cassette (step 125 (126)). When steps 125 and (126) are completed, or when a negative result is obtained in step 124, it is determined whether all the wafers that require inspection have been inspected (step 127), and when a positive result is obtained, the wafer If a negative result is obtained, the process returns to step 101.

During the check in step 121 (122), the CPU
63 repeatedly executes two loops formed by each step of the judgment shown below, that is, the loop of. If a positive result is obtained in both steps 101 and 102, or if a positive result is obtained in any of steps 123, 124, or 127, these loops are exited. Therefore, the wafers are exchanged sequentially from the stage where the inspection has been completed, and new fine alignment and inspection are performed. This process is repeated until there are no more wafers to be inspected. Furthermore, each time a wafer is replaced, the optical fiber 7.8 is moved to switch the illumination light to illuminate the newly replaced wafer. Furthermore, both stages 54A
While the wafers W, , , W placed in wafers W, , 54B are being simultaneously scanned, both of them are maintained in the illumination light-blocking state.

In this embodiment, there are two stages for fine alignment, and two sets of alignment optical systems and illumination optical fibers are provided.
However, the present invention is not limited to this (it goes without saying that if there are three or more stages, the number of alignment optical systems and optical fibers will increase accordingly).

〔Effect of the invention〕

As described above, according to the present invention, the light input end of the optical fiber that guides the illumination light to the test object is moved to switch the optical path, so multiple illuminations can be performed with a single light source with a simple configuration. This also has the advantage that optical adjustment is easy and the illumination device can be provided at low cost. If the illumination light passing through the aperture of the aperture member is constructed to be able to be blocked at the intermediate portion between the optical fibers as in this embodiment, the optical path switching means can also serve as the light blocking member for all optical paths, and the drive control thereof can be performed. It also has the advantage of being easy.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, and FIG.
FIG. 3 is a block diagram of an alignment apparatus incorporating the embodiment shown in the figure, and FIG. 3 is a flowchart showing the operation of the alignment apparatus of FIG. [Explanation of symbols of main parts] 1-111 light source 4-111 aperture member 4A---1 aperture 5-111 optical path switching moving member (optical path switching means) 7.
8---One optical fiber 7A, 8 A---One light incident end 12, 22---One objective lens 13.23---One imaging lens

Claims (2)

[Claims] (1) An aperture member having an aperture through which illumination light from a light source passes, a plurality of flexible optical fibers each guiding the light that has passed through the aperture to a plurality of test objects, and light incidence ends of the plurality of optical fibers. and an optical path switching means that is selectively movable so that each of the light incident ends coincides with the aperture. (2) The optical path switching means has an intermediate portion 5A that blocks light passing through the opening, and the light input end of the optical fiber is supported on the outside of the intermediate portion 5A. An optical path switching device for a lighting device according to claim 1.